The present invention relates to electronic circuitry used in semiconductor devices. More particularly, the invention relates to a static sense amplifier circuit for sensing the differential voltages on two input lines and producing a digital output signal indicative of the relationship of the voltages on the two input lines.
Sense amplifiers are commonly used in many electronic circuits. A typical differential sense amplifier receives first and second input signals and generates an output signal indicative of a relationship between the two input signals. For example, an output signal of first potential may be generated to indicate that the first input signal has a higher potential than the second input signal. An output signal of different potential may be generated to indicate that the first input signal has a lower potential than the second input signal.
One problem encountered in some known sense amplifiers is caused by a combination of the circuitry and the characteristics of the transistors used to construct the sense amplifier. If field effect transistors are used, the gate capacitance presented at the input of an amplifier stage normally adds substantial delay to the preceding amplifier stage, slowing down the response of the circuit. Another problem with some known sense amplifiers is excessive power consumption. Yet another problem in some sense amplifiers is extreme sensitivity to process variations. In view of the foregoing problems, there is a need to provide a sense amplifier that provides a combination of high speed, low power consumption, and process tolerance.